The invention concerns a linear rolling bearing element for mounting on a running surface of a guide rail, said element having a carrier body comprising, for a rolling element circuit, a load-bearing zone and a return channel that are parallel to a direction of movement of the carrier body while being connected to each other by two deflecting channels disposed in head pieces that are arranged on ends of the carrier body, said head pieces comprising lubricant ducts, while a rolling element guiding means in form of a plastic coating is arranged in the load-bearing zone, the return channel and the deflecting channels.
In a bearing element of the pre-cited type known from the document DE 43 31 014 C2, an inner retention plate and an outer retention plate form an assembled unit that serves to retain a front wiper and also comprises channels for the distribution of lubricant.
It is an object of the invention to facilitate and quicken the mounting of the guide carriage formed by the carrier body and the head pieces.
This and other objects and advantages of the invention will become obvious from the following detailed description.
The invention achieves the above objects by the fact that each head piece is formed by a cage arranged on an end of the carrier body and by a one-piece sealing plate comprising lubricant ducts, said plate being adapted to and disposed on the cage. This results in a reduction of the number of components making up the bearing element so that less screw connections are required compared to prior art bearing elements. Besides this, the number of joints are also reduced, so that dirt particles from the outside cannot enter the structure so easily. The fact that the plastic component of the carrier body, designated as a cage, is adapted in the deflecting region to the sealing plate that acts as a lubricant distributor, results in an improved sealing against the entry of dirt particles from the outside. The deflecting regions of the bearing element of the invention are fully enclosed on all sides i.e., they are encapsulated. The importance of such an arrangement increases when used for the operation of guide carriages with blocking air (internal overpressure).
A sealing strip comprising a lubricant duct can be integrally formed on the sealing plate of the bearing element. The sealing strip can comprise re-lubricating bores through which the lubricant duct of the sealing strip and the lubricant ducts of the sealing plate are open toward the exterior. The sealing strip can comprise an upper re-lubricating bore and/or two side lubricating bores, and can further comprise an end re-lubricating bore.
For forming the deflecting channels, deflecting cups can be fixed on the inner surface of the sealing plate. Further, an elastic separating layer can be arranged between the inner surface of the sealing plate and each deflecting cup.
The two sealing plates of the bearing element of the invention are arranged mirror-inverted on the carrier body and are connected to each other by two longitudinal seals that are inserted or pushed into appropriately configured receptions of the carrier body.
The sealing plate can be positioned and fixed on its associated and appropriately adapted cage on the carrier body by integrated clips, clamping lugs, retaining lugs or bores, so that screw connections are not required for this purpose.
For sealing the deflecting zones of the carrier body from the outside, sealing elements, for example an O-ring seal, can be disposed in the sealing plates.
The invention will now be described more closely with reference examples of embodiment illustrated in the appended drawings.